An electrical switchgear is disclosed.
In particular, a line circuit breaker is disclosed which is used for disconnecting loads in the event of a short circuit or excess current. Such a breaker can be used in combination with, for example, motor circuit breakers and fault-current circuit breakers.
A line circuit breaker has in its interior an electromagnetic trip which has a plunger-type electromagnet, with a core and a moving armature around which a coil is wound. In the case of a short circuit, the armature moves and, on the one hand, impacts the contact lever so that the contact point is rapidly opened; on the other hand, it also effects a continuing opening of the contact point via a latch. The thermal trip which is constructed as a bimetallic trip in most cases exclusively acts on the latch to effect the continuing opening of the contact point. The bimetal is constructed in most cases as a strip which bends out due to the different coefficients of expansion of the metals joined to one another. Naturally, a strip of a shaped memory alloy can also be used instead of a thermal bimetal.
In the switch S2 of the company ABB Stotz Kontakt GmbH, Heidelberg, the latch is supported between two boards which are connected to one another and which also form or accommodate the bearing point for the corresponding components forming the latching point. In this switch, the electromagnetic trip is located between the thermal bimetal and the contact lever.